I've used this method for users and it works like a charm, but when I attempt it with groups I get a big fat fail.
Specifically:
The user IS granted the appropriate access to a site via adding a group the user is a member of to the appropriate site-specific group (site_ABC_managers, for instance), but the site fails to show up in the user's My Sites list.
When the user searches for the site and clicks through to it, he has 2 Request To Join buttons at the top right of the screen - clicking either of them grants a pop-up success window and then the site appears in the user's My Sites list. Craziness, I know!
Anyone have any ideas about this? Ideally, adding a group of users to a site-specific group would work exactly like adding users, but that's not the case.
Oh, and I'm running 4.2.c on a CentOS x64 box. Thanks!